do_mq_open(): move all work prior to dentry_open() into a helper

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index a2483524b6333eb607deed10cb774e79c41ce8ba..e8a872e9c8083e65b9f36f6d65cbf26f8c359805 100644 (file)
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -713,34 +713,44 @@ static void remove_notification(struct mqueue_inode_info *info)
        info->notify_user_ns = NULL;
 }
 
-/*
- * Invoked when creating a new queue via sys_mq_open
- */
-static int do_create(struct ipc_namespace *ipc_ns, struct inode *dir,
-                       struct path *path, int oflag, umode_t mode,
+static int prepare_open(struct dentry *dentry, int oflag, int ro,
+                       umode_t mode, struct filename *name,
                        struct mq_attr *attr)
-{
-       return vfs_mkobj(path->dentry, mode & ~current_umask(),
-                       mqueue_create_attr, attr);
-}
-
-/* Opens existing queue */
-static int do_open(struct path *path, int oflag)
 {
        static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
                                                  MAY_READ | MAY_WRITE };
        int acc;
+
+       if (oflag & O_CREAT) {
+               if (d_really_is_positive(dentry)) {     /* entry already exists */
+                       audit_inode(name, dentry, 0);
+                       if (oflag & O_EXCL)
+                               return -EEXIST;
+               } else {
+                       if (ro)
+                               return ro;
+
+                       audit_inode_parent_hidden(name, dentry->d_parent);
+                       return vfs_mkobj(dentry, mode & ~current_umask(),
+                                 mqueue_create_attr, attr);
+               }
+       } else {
+               if (d_really_is_negative(dentry)) {
+                       return -ENOENT;
+               } else {
+                       audit_inode(name, dentry, 0);
+               }
+       }
        if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
                return -EINVAL;
        acc = oflag2acc[oflag & O_ACCMODE];
-       return inode_permission(d_inode(path->dentry), acc);
+       return inode_permission(d_inode(dentry), acc);
 }
 
 static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
                      struct mq_attr *attr)
 {
        struct path path;
-       struct file *filp;
        struct filename *name;
        int fd, error;
        struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
@@ -767,39 +777,14 @@ static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
        }
        path.mnt = mntget(mnt);
 
-       if (oflag & O_CREAT) {
-               if (d_really_is_positive(path.dentry)) {        /* entry already exists */
-                       audit_inode(name, path.dentry, 0);
-                       if (oflag & O_EXCL)
-                               error = -EEXIST;
-                       else
-                               error = do_open(&path, oflag);
-               } else {
-                       if (ro) {
-                               error = ro;
-                       } else {
-                               audit_inode_parent_hidden(name, root);
-                               error = do_create(ipc_ns, d_inode(root), &path,
-                                                oflag, mode, attr);
-                       }
-               }
-       } else {
-               if (d_really_is_negative(path.dentry)) {
-                       error = -ENOENT;
-               } else {
-                       audit_inode(name, path.dentry, 0);
-                       error = do_open(&path, oflag);
-               }
+       error = prepare_open(path.dentry, oflag, ro, mode, name, attr);
+       if (!error) {
+               struct file *file = dentry_open(&path, oflag, current_cred());
+               if (!IS_ERR(file))
+                       fd_install(fd, file);
+               else
+                       error = PTR_ERR(file);
        }
-       if (error)
-               goto out;
-       filp = dentry_open(&path, oflag, current_cred());
-
-       if (!IS_ERR(filp))
-               fd_install(fd, filp);
-       else
-               error = PTR_ERR(filp);
-out:
        path_put(&path);
 out_putfd:
        if (error) {